This proposal concerns a group of neurosecretory peptides produced by neurons in the relatively simple nervous system of Aplysia. We aim to characterize their transitions through somatic pools prior to their commitment to axonal transport and to use peptide maps to study their structural alterations during processing events. We will continue studies designed to identify the neurons that synthesize them. We intend to determine whether stimulation of their secretion will increase their rate of axonal transport or the amounts in which they are transported.